Kleenmaid once employed hundreds of people, had 600,000 customers nationwide and turned over more than $100 million a year, Mr Young told Brisbane District Court on Thursday.

The firm collapsed in 2009 when major creditor Westpac put Kleenmaid into administration, although the Crown has said the rot set in years before.

"The evidence will show that I am here [due] solely to the unfortunate collapse of the Kleenmaid company in 2009," Mr Young said.

Mr Young said influential factors in the collapse included "growth that had occurred ahead of what was expected" and the impact of the global financial crisis from late 2008.

The Maroochydore man is accused of dishonestly incurring debts, including when allegedly a director of Edis Service Logistics, Kleenmaid's former spare parts arm.

One of the charges related to dishonestly acquiring a $13 million loan from Westpac.

Mr Young said the Crown made significant allegations, "most importantly a fundamental attack on my honesty".

He told the jury they might hear of "big dollar" sums.

"I would ask that you keep in context the size of the Kleenmaid business as [it] developed over the many years it was operating."

Crown prosecutor Stephen Keim earlier said Mr Young was a director, or effectively acting as a director, when Edis incurred some of the debts.

"After examination of witnesses, you may find my interest was entirely understandable," Mr Young said.

The businessman responded to Mr Keim's claims that an "elaborate" 2007 restructure of the Kleenmaid group was a facade.

Mr Young said there were good reasons for the restructure, including "unexpected triple bypass heart surgery" he had in 2005.

The restructure intended to reduce Mr Young's involvement "from the levels that had become the norm" some two decades after Kleenmaid was founded.

Marc Robinson, formerly of ASIC's national insolvency coordination unit, was the first witness to be cross-examined.

One of his jobs was to visit firms showing signs of insolvency and meet directors.

He first visited Kleenmaid in October 2006.

Mr Young asked if that visit resulted from a disgruntled Kleenmaid employee's complaint.

"That is something that you have told me," Mr Robinson replied, before saying an ASIC colleague of his from the Sunshine Coast knew about "the high turnover of staff in the accounting division" of Kleenmaid.

Mr Robinson said Mr Young provided information about the business which was "certainly adequate" after that visit.